That's not nearly enough information for anyone to help you.
The Mail::Send module seems to just be a framework. Are you sending the email through an SMTP server, such as your ISP? You very likely are, so you need to configure whatever perl module you are using so it knows how to send to that server.
Take a look at
Net::SMTP. You can either use it directly or as an argument to
Mail::Mailer, which you can use as an argument to Mail::Send. I think.
Nothin's simple, is it?